ARM: S5PV310: Fix on Secondary CPU startup

Following occurs on boot message without this patch.
    CPU1: processor failed to boot
    Brought up 1 CPUs
    SMP: Total of 1 processors activated...

This patch adds SYSRAM mapping for fixing Secondary CPU startup.
    CPU1: Booted secondary processor
    Brought up 2 CPUs
    SMP: Total of 2 processors activated...

Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>